King's Highway 7A (Alt) was created in 1961, when the Highway 7 designation was added to the existing route of Highway 15 between Carleton Place and Ottawa. The
Highway 7A (Alt) designation was applied to a bypassed section of Highway 15 between Ashton and Stittsville, which was known as
Highway 15A (Alt). The bypassed route of Highway 15 through Ashton and Stittsville (via
Ashton Station Road, Ormond Road, Flewellyn Road, Huntley Road and Main Street) became Highway 15A (Alt) after a Highway 15 relocation project was
completed in 1956. The concurrent route of Highway 7A (Alt) and Highway 15A (Alt) was decommissioned in 1969, when the entire route was transferred to the Township of
Beckwith, the Township of Goulbourn and the Village of Stittsville, effective April 1, 1969.